'The prevalence of exercise-induced laryngeal obstruction (EILO) among children with asthma': a study protocol of a prospective cross-sectional study

Introduction: Exercise-induced symptoms are common within the paediatric population and can hamper participation in sports and play, negatively impacting cardiorespiratory activity and social interaction. Exercise-induced bronchoconstriction (EIB) is a prevalent and well-known cause of exercise-induced symptoms. Especially in children with asthma, exercise-induced symptoms are often primarily attributed to EIB, although other causes of exercise-induced symptoms are numerous. In patients with exercise-induced laryngeal obstruction (EILO), narrowing of the larynx during exercise causes symptoms similar to those of EIB. The reported prevalence of EILO among adults with asthma ranges from 13% to 47%, whereas EILO prevalence among the general adolescent population is 5%–8%. Currently, the prevalence of EILO among asthmatic adolescents has not yet been investigated. In this study, we aim to investigate the prevalence of EILO among adolescents with asthma. Knowledge of EILO prevalence in this specific group can help to determine the position of the continuous laryngoscopy during exercise (CLE) test in diagnostic guidelines for adolescents with asthma.